Retractors have been used in surgical procedures to provide access to a surgical site in the body. These retractors enable a surgeon to visualize a surgical site as well as enable a surgeon to insert tools into the body to perform a surgical procedure. One type of retractor has two or more blades which are spread apart generally parallel to each other to create an opening. These retractors require relatively large incisions and result in tissue being uniformly stretched or dissected from the exterior of the body at the skin down to a surgical site. Such a retractor may result in significant trauma to the body and may necessitate long recovery time.
Other types of retractors have blades which are pivotable with respect to each other. Such a construction allows the blades to be opened at an angle with respect to each other and requires a smaller skin incision than parallel spreading retractors. The use of pivotable retractors results in tissue proximate the skin level being stretched less than tissue at the surgical site. These retractors may be useful, for example, for pedicle screw fixation where the trajectories of the pedicle screws, viewed from the side of the body, converge due to the natural lordosis in the lumbar spine. This convergence may necessitate a shorter skin incision compared to the opening that needs to be created directly above the lamina and the pedicles.
Furthermore, some retractors have portions which may be expanded inside the body to provide access to a surgical site. Pivotable and expandable retractors often require separate and/or complex mechanisms to control the spreading of the blades and/or expansion of the retractor. Therefore, it is desirable to have a device for providing access into the body which requires only a small skin incision, causes the least amount of trauma to the body and, at the same time, is relatively simple to operate.